石墨炉原子吸收光谱法测定锡铅焊料中铝

Determination of aluminum in tin-lead solders by graphite furnace atomic absorption spectrometry

以硝酸（1＋2）-盐酸（1＋1）溶解样品,采用盐酸沉淀大部分铅及银,在16g/L柠檬酸、0.12mol/L盐酸介质中,取澄清液直接采用石墨炉原子吸收光谱法测定锡铅焊料中铝。结果表明：在选定的酸度介质中,不需要挥锡,锡也不会水解;大部分铅及银以氯化物形态沉淀于底部,无需用盐酸处理的脱脂棉-纸浆过滤分离银及铅沉淀,直接取澄清液进行测定即可;样品溶液保持清亮时间长,样品中锡及共存元素不干扰测定。方法线性范围为3.00~100.00μg/L,检出限为4.04μg/L。将方法应用于锡铅焊料标准物质中铝的测定,结果与认定值或GB/T10574.13—2003采用的电感耦合等离子体原子发射光谱法（ICP-AES）一致,相对标准偏差为6.2%~8.9%。

The sample was dissolved with nitric acid （1＋2） and hydrochloric acid （1＋1）. Most lead and silver were precipitated by hydrochloric acid. Then, the supernatant liquid in medium of 16 g/L citric acid- 0.12 mol/L hydrochloric acid was directly analyzed by graphite furnace atomic absorption spectrometry to determine the content of aluminum in tin-lead solder. The results showed that the tin was not hydrolyzed without volatilization in selected acidity medium. Most lead and silver were precipitated on the bottom in form of chlorides. The supernatant liquid could be directly analyzed without filtration to remove silver and lead precipitations by degreasing cotton-paper pulp which was treated by hydrochloric acid. The clarifica- tion of sample solution could last for long time. The tin and coexisting elements in sample did not interfere with the determination. The linear range of method was 3.00-100.00 μg/L, and the detection limit was 4.04 μg/L. The proposed method was applied to the determination of aluminum in certified reference materials of tin-lead solder. The found results were consistent with the certified values or those obtained by inductively coupled plasma atomic emission spectrometry （ICP-AES） in GB/T10574.13--2003. The rela- tive standard deviations （RSD） were between 6.2% and 8.9%.